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I was going to wait until I had a few more miles on my 406 (it only has 700 miles on it) before I put it on the dyno, but I just couldn't wait. The #'s turned out better than I expected for a motor that still needs to be broken in and dyno tuned.
Rear wheel HP: 342 @ 5,000 RPM
Rear Wheel Torque: 424 @ 3,750
Figuring in 15-20% driveline loss this should equal 400-430 net hp at the flywheel and 500-530 net tq at the flywheel. These #'s were generated while the motor war running pretty hot at around 210 and with no dyno tuning and are corrected for elevation and temp by the dyno. With a cooler motor and some tuning, there may still be a few HP left.
If anyone has a dragstrip simulator, please crunch the #'s for a 3,100 pound car with 4.11 gears and around a 1.90 60 ft time.
I have the RPM cam. It is a great cam for a mild engine. My car has a very slight lope at idle, but pulls strong from 1000 rpm on up. If I were to change anything, I would probably go with a slightly bigger roller cam.
It should be possible to get even a bit more torque than that out of your 400+ small block. I got 490 lb-ft way back when I dynoed mine. It only has 12 more cubes than yours.
What kind of intake are you running? My run was with my TPI system, which builds great torque.
On the 60' front... You'll have a lot of trouble hooking the torque up. I've yet to get under 2.0 seconds.
Were you getting 490 torque at the rear wheels or the flywheel?
I would like to go to a TPI system for cold starts and to get double digit gas mileage. I just haven't seen a TPI system for under two grand that is workable for the average joe. A couple of my friends have tried and given up on FI systems for their smallblocks.
Mike,
There is a TPI system for sale for $800 on consignment at On-Track Performance, in Denver, Colorado. (303)788-0898.
Keep in mind that even though the GM tuned port is wonderful for torque, it is NOT a high rpm solution. They were designed for a 305 motor. I have mine on a 355 engine in an 86 IROC, and it runs fabulously with a 221/221 degree Isky hyd. cam (@ 0.050") with 0.465" lift int/exh. However, 5000 is absolute tops for me.
On a larger 406, look for a serious increase in torque, but probably nothing north of 4500 rpm. If that's alright with you, give On-Track a call and buy it. They'll ship it anyway you want.
Were you getting 490 torque at the rear wheels or the flywheel?
Now that you mention it, I remember thinking that some kind of conversion factor being applied to the printout. Perhaps it had derived the engine torque from the measured rear wheel torque. I know it would have had to convert the torque given the gearing, but what I don't know is whether some kind of percentage multiplier was thrown in there. I won't bet either way; I'll have to see if I can go find that dyno report.
If it were true that 490 was the extrapolated value in my case, then your engine seems to be right on a par with mine, if maybe even a little more torquey. My torque peak came out at about 3800 RPM, with a 4800 RPM horsepower peak.
I CAN say this with certainty: 400+ small blocks are :cool:!
It is interesting to see your torque figures. Your 424 tq is very impressive at the rear wheels. Probably over 500 at the crank. Intake manifold selection was one of the things I agonized most over. The rpm air gap does make torque, and seems to provide lots of top end hp. Judging by your dyno results, I probably gave up some torque and maybe gained a little hp by going with the Weiand Team G 7530.
I bet the car is a blast to drive!! :cool: :cheers: :chevy